In the London Protocol, the three protecting powers (United Kingdom, France and Russia) establish the borders of Greece.

The London Protocol of 1829 was an important diplomatic agreement connected to the Greek War of Independence. Signed by Britain, France, and Russia on February 3, 1830 by the Gregorian calendar, though often discussed in relation to the negotiations of 1829, it formally recognized Greece as an independent state rather than merely an autonomous territory under Ottoman rule. This marked a major shift in European diplomacy, because the Great Powers moved from trying to manage the conflict within the Ottoman framework to accepting that a new sovereign state would emerge. The protocol reflected both humanitarian sympathy for the Greek cause and the strategic interests of the powers, each of which wanted influence in the eastern Mediterranean.

The background to the protocol lay in years of conflict beginning with the Greek uprising in 1821. Earlier agreements, such as the Treaty of London in 1827, had aimed at mediation between the Greeks and the Ottoman Empire, but events on the ground changed the political situation. The naval Battle of Navarino in 1827, where allied fleets destroyed the Ottoman-Egyptian fleet, weakened Ottoman control dramatically. At the same time, Russia’s war with the Ottoman Empire in 1828–1829 increased pressure on the sultan. By the end of the decade, it had become clear that some form of Greek self-government was unavoidable, and the powers used the London Protocol to define the terms of the new Greek state.

The protocol also mattered because it established the framework for modern Greece’s international status, even though the borders it proposed were limited and the final settlement would later be revised. Greece was to become a hereditary monarchy under the guarantee of the Great Powers, showing that its independence came with significant outside supervision. This reveals a broader pattern in nineteenth-century European politics: nationalist movements could succeed, but usually only when their goals aligned with the interests of stronger states. In that sense, the London Protocol was not just a victory for Greek independence, but also an example of how the Concert of Europe shaped the map of the continent.